Treating resev glues and product



United States Patent TREATING RESIN GLUES. PRODUCT PRODUCED.

Carl F. MacLagan, Bainbridge, N. Y.,, and. Lawrence Bradshaw, deceased, lateofiBainbridge, Ya, by The Borden Company, New. York, N. Y.,. assignee No, Drawing. Originall No. 2,358,683, dated September 19, 1944, Serial No, 43 ,360, February 25,1942. Application, for reissue, December- 15, 1951, Serial No. 261,908

11 Claims. (Cl. 117100):

Matter enclosed: in heavy brackets]: appears in. the original patent but forms no part of:- this reissue specification; matter printedi in italics indicates the additions made. by reissue.

During the last few years, glues and. materials of an; adhesive character have been. used, to a. substantial extent, containing. water soluble synthetic resins, notably water-soluble urea iormaldehyde resin or water-soluble phenolic. resin. For getting. products. wh ch dissolve (-or become dispersed) in water on aqueous liquids, 1b is advisable to employ the. said resinv in a. very finely divided condition, and particularly the spray-dried. material has. been found advantageous, the particles being perhapssomewhat porous; and dissolving more readily than would.

be. the. case if the hard-resin weresimply. comminuted, to a fine powder.

The fine powder obtained. by spray-drying a solution (e. g. an aqueous. solution) of 'synthetic resin (notably urea-formaldehyde resin), has. certain. undesirable physical properties; (1). it. is very dusty, (,2) it, tends totcake;

together, (3) it tends to; entrap-ain so thati on mixingwith water a. foamy glue. often. results, (4.) It tends to clingto the containervand,to-,the.;utensils; (such. asshovels or scoops). used; in handling it, (5) it tends to lump when,

being, mixed with water inproportions. to former spread able fluid glue.

We; have now found; that, theseobjectionable properties can. be greatly reduced. and often, wholly eliminated. by coating; the. particles of. the powder with, anoil, (mineral, vegetable or animal), or anorganic-liquid havinggan; oily character. (for example tributyl phosphate, diethyl phtha1=v ate). In general.layingladust withoil is; not; new and,

ithas heretofore.been-practiced to oil a.dry, glue base or the-casein, seedmeal etc., usedin making same. We

believe, however,- that it is a-new. discovery thatthe-said; water-soluble. resin powder and oilrare compatible, that the. oiled powder is readilymiscible-withwater and that theadhesive strengthof the resin glue is not. impaired by the small amount of oil or oil-like fluid required to prevent dusting. Further, by oiling the material the tendency to cake is. very greatly'lessened thoughnot always.

entirely overcome by this treatment. Thetreated powder mixes more smoothly and more easily with water than, the untreated powder, substantially without lumping or foaming.

In this. connection it is calledto attention, that the resins used-inthe present invention are of the type that are soluble in water. The term soluble does not neces:

sarily imply that when the fine resin powder (alone or- The oil or.

2 oil-y. liquid is sprayed or poured upon it with the mixer (which may be atumblingbarrel) running, and the mixing continued for twenty to thirty minutes or as long as may be required to give a thorough blending...

Wev prefer to. use. about 1% of the selected oil. or. oilyliquid or mixture of the. same. The-oil; maybe; a mineral oil. such as a. dressing oil or lightlubricating oil, a vegetable oil such as cottonseed oil, pine oil or oil of Verbena; an animal oil such assperiri oil Other oils which we have found to be satisfactory are the oils of cedar, citronell'a, lemongrass, sassa-fi'as andrnenhaden oil. A very suitable mineral oilis one having a specific gravity of 0.88, a Saybol't viscosity of about 105 at F., and a flash point above 300 Or we. may use an organic liquid which although not strictly anoil, possesses an oillike character capableof'performing the same function inabating the dust and otherwise improving the-working qualities of the powder as, recited" above, e. g., tributyl phosphate or diethyl phthalate'. A mixture of oils or a mixture of one or morexoils. with one or more organic liquids having the desired properties may also be used. The preferred oils are those which donot'becomerancid. The aboveoils andoiliy materials are; insoluble or atiany' event substantiallyinsoluble) in water.

Some powders may require more or-less' than 1% of the oil. Wemay use from about 025% to. 5% accord.- ing; to the nature of the powder but in most' cases about 0.5 to 2.0% is suitable. We hayefbundthat. an amount; ofoil up to about-5% of the weightLofi the powder does; not substantially reducethe adhesive strength ofthe glue prepared from'the resin powder.

We refer above tourea-formaldehyde resin, but We have also employed the above described process in the treatment of water-soluble, phenolic resin powders for the same purpose, with-marked=success.

We desire to, call attention to, the: factthat the: oili applied is, by means ofthe: agitation of. the material (and; if desired, assisted. by the; fact of the oil being: sprayed' upon, the mass. of. finely comminuted material: consisting" largely or wholly of the very fine spray-dried:water-soluble synthetic resin, in very large part at least, spreadout into theformof. ayery thin.film-.on;the particles of? such resin). It is an .iinportantfunctional adyantage'also, that. the application of. the-- oil i to thefine par-ticles t of the soluble resin, which. already. show a substantial. tendency to: clingto, container wallsand tov tools. (e. g. shovelstandi scoops) does notincrease this tendency, but: intact greatly; reduces the same. This. is .an important advantage of; the present. invention. In. this connection, it may be noted: that. a similar oiling of powdered rosin, would greatly in? crease its tendency to stickrtow surfaces.

. As stated above, the untreatedv syntheticresinpowdent is very dusty. A dusty powder is objectionable in several; ways.v The, dust. raisedinhandling, for. example. in. packingthe-powder or intransferring the powder from thes container toithe gluepot or. glue mixing, machine, tends to float in the. air andto be carried tofardistance'beforea It. settles on the-workmens. skin .and;may set.-up' an. irritationz settling, thuscontarninating the whole workroom.

dueto the formaldehyde or other chemical and mayycause itching or irritation or. eyenacutegdermatitis.

especially objectionableinthis respect. T he process. ofoilingthe powder as. describedherein, mitigates the dis-- persaloidust inhthe. air. audits attendantv nuisance and:

loss.

Secondly, the untreated powders tendflto agglomerate or cake together in storagev and. the agglomerations. form.

namely that of addinga substantially inert mineral'powder- Itiis also troublesome ,if; inhaled, the, phenolic. resin powders being.

may actually increase the dustiness, which in turn can be reduced by oiling as described.)

Further, the untreated po ders when dropped on the surface of water in the mixer in preparing the liquid glues tend to form clusters (consisting of a core of dry or imperfectly wetted powder surrounded by an envelope of partly dissolved resin). The oiled powders however resist wetting momentarily, so that in the present invention the grains are scattered throughout the liquid and dissolve without clustering, providing a more uniform mix free from lumps. The oiled powders also release trapped air more readily, so that there is less tendency to produce foamy glues.

For the purpose of more completely explaining how the present invention is to be performed, we give the following examples, to which the invention is not restricted.

EXAMPLE 1 100 pounds of a synthetic resin powder prepared for example by spray drying an aqueous solution of a urea formaldehyde resin, and containing about of residual moisture, is charged into a suitable mixer such as a tumbler 0r spiral mixing device. While operating the mixer, about one-half pound of oil of cedar is sprayed on to the powder and the mixing is continued for about minutes. The oiled powder is then ready for, use or may be packaged and stored.

EXAMPLE 2 100 pounds of a water-soluble phenol-formaldehyde resin powder is placed in a vessel provided with eflicient mixing blades. With the mixer running, about one-half pound of a thin mineral oil having, for example, a specific gravity of about 0.88 and a viscosity of about 105 Saybolt, is allowed to drop on to the powder at room temperature. After the oil has been added the mixing is continued for about minutes to obtain a thorough blending. The oiled powder is then ready for being dissolved in water.

The powdery mixtures so produced are suitable for mixing with water to form liquid glues, without lumping or foaming.

EXAMPLE 3 Like Example 1, but instead of the resin alone, we can use a mixture of 4 parts of the resin with 1 part of wheat flour or wood flour (these proportions can be varied substantially, and/or other components can be added if desired).

We claim:

1. In handling dry comminuted potentially adhesive material containing a substantial amount of a watersoluble synthetic resin in finely divided dust-forming condition, the herein described improvement which comprises applying thereto a small percentage of a fluid oily liquid which is substantially insoluble in water, and spreading out said oily liquid, at least in large part into the form of films carried upon the said fine particles, whereby the tendency to form dust and the tendency to cling to containers and tools are greatly reduced, and the said finely divided resin becomes more easily miscible with aqueous diluents.

2. A process of treating spray-dried water-soluble ureaformaldehyde resin in a finely dividedstate, which comprises adding to the same not over 5% of a substantially water-insoluble fluid oily material, and spreading out said fluid oily material, at least in large part, into the form of films on said finely divided resin.

3. A glue base which contains a substantial amount of a watersoluble synthetic resin in a, finely divided condition, such base being coated with not substantially more than 5% of a fiuid water-insoluble oily material, such oily material being, in large part at least,spread out in the form of films on the finely divided powder, and which glue base can be uniformly mixed with water more easily than could the said finely divided powder without the oily material being added thereto.

4. A glue base which contains a substantial amount of a Water-soluble urea-formaldehyde resin in a finely divided condition, such base being coated with not substantially more than 5% of a water-insoluble fluid oily material, such oily material being, in large part at least, spread out in the form of films on the particles of such finely divided powder, and which glue base can be uni- 4 forrnly mixed with water more easily than could the said finely divided powder without the oily material being added thereto.

5. In handling dry comminuted potentially adhesive material containing a substantial amount of a watersoluble synthetic resin in finely divided dust-forming condition, the herein described improvement which comprises applying thereto a small percentage of a fluid oily liquid which is substantially insoluble in water, comprising terpineol, and spreading out said oily liquid, at least in large part into the form of films carried upon the said fine particles, whereby the tendency to form dust and the tendency to cling to containers and tools are greatly reduced, and the said finely divided resin becomes more easily miscible with aqueous diluents.

6. In handling dry comminuted potentially adhesive material containing a substantial amount of a water-soluble synthetic resin in finely divided dust-forming condition, the herein described improvement which comprises applying thereto a small percentage of a fluid oily liquid which is substantially insoluble in water, comprising tributyl phosphate, and spreading out said oily liquid, at least in large part into the form of films carried upon the said fine particles, whereby the tendency to form dust and the tendency to cling to containers and tools are greatly reduced, and the said finely divided resin becomes more easily miscible with aqueous diluents.

7. In handling dry comminuted potentially adhesive material containing a substantial amount of a water-soluble synthetic resin in finely divided dust-forming condition, the herein described improvement which comprises applying thereto a small percentage of a fluid oily liquid which is substantially insoluble in water, comprising diethyl phthalate, and spreading out said oily liquid, at least in large part into the form of films carried upon the said fine particles, whereby the tendency to form dust and the tendency to cling to containers and tools are greatly reduced, and the said finely divided resin becomes more easily miscible with aqueous diluents.

8. In handling dry comminuted potentially adhesive material containing a substantial amount of a watersoluble synthetic resin in finely divided dust-forming condition, the herein described improvement which comprises applying thereto a small percentage of a fluid oily liquid which is substantially insoluble in water, comprising cottonseed oil, and spreading out said oily liquid, at least in large part into the form of films carried upon the said fine particles, whereby the tendency to form dust and the tendency to cling to containers and tools are greatly reduced, and the said finely divided resin becomes more easily miscible with aqueous diluents.

9. In handling dry comminuted potentially adhesive material containing a substantial amount of a water-soluble synthetic resin comprising phenol formaldehyde condensate in finely divided dust-forming condition, the herein described improvement which comprises applying thereto a small percentage of a fluid oily liquid which is substantially insoluble in water, and spreading out said oily liquid, at least in large part into the form of films carried upon the said fine particles, whereby the tendency to form dust and the tendency to cling to containers and tools are greatly reduced, and the said finely divided resin becomes more easily miscible with aqueous diluents.

10. In handling dry comminuted potentially adhesive material containing a substantial amount of a watersoluble synthetic resin comprising urea-formaldehyde condensate in finely divided dust-forming condition, the herein described improvement which comprises applying thereto a small percentage of a fluid oily liquid which is substantially insoluble in water, and spreading out said oily liquid, at least in large part into the form of films carried upon the said fine particles, whereby the tendency to form dust and the tendency to cling to containers and tools are greatly reduced, and the said finely divided resin becomes more easily miscible with aqueous diluents.

11. In handling dry comminuted potentially adhesive material containing a substantial amount of a watersoluble synthetic resin comprising urea-formaldehyde resin in finely divided dust-forming condition, the herein described improvement which comprises applying thereto a small percentage of a fluid oily liquid which is substantially insoluble in water, comprising pine oil, and spread ing out said oily liquid, at least in large part into the form of films carried upon the said fine particles, whereby 6 the tendency to farm dust and the tendency to cling to 2,056,458 Howald Oct. 6, 1936 containers and tools are greatly reduced, and the said 2,162,690 Anderson June 20, 1939 finely divided resin becomes more easily miscible with 2,245,040 Marks June 10, 1941 aqueous diluents. 2,358,683 Bradshaw et a1. Sept. 19, 1944 f C d th in h 5 2,535,020 Stephan Dec. 19, 1950 Re erences ite in e e o is patent or the original patent FOREIGN PATENTS 534,095 Great Britain Feb. 27, 1941 UNITED STATES PATENTS 1,979,380 Gaxdner Nov. 6, 1934 10 

